Imaging of Defects in Additively Manufactured Alloys Using Betatron X-Rays

Betatron radiation is a synchrotron-like X-ray emission generated from the oscillations of trapped relativistic electrons during laser wakefield acceleration (LWFA). Betatron sources are broadband keV X-rays with small source sizes and few-femtosecond pulse durations, ideal for high-resolution phase contrast and X-ray imaging of dense materials. Here, we present the characterization (spatial resolution and acquisition time) of the betatron X-rays from different gases to study their ability for high-resolution imaging of micrometer-scale defects in additively manufactured (AM) aluminium-silicon alloys. Characterization of the X-ray source spectrum, spatial resolution, source size and betatron emission length was performed using the Advanced Laser Light Source in Varennes, Canada. Upcoming applications of these sources for high-resolution, high-throughput 3D tomography of porosity evolution of AM alloys under tension will be discussed.